In case you don't see what RIOT is trying to pull with the LE Warwick skin & Vet shop
They want you to drop 150k Blue Essence on it (among a lot of other overpriced nonsense in the upcoming veteran shop) because if you spend most or all of your BE, you won't be able to buy new champions with BE and will be forced to use cash.
Remember, you won't be able to accumulate BE by playing games like you can accumulate IP currently. You don't get BE by playing games, you don't actually get anything. After playing enough games to level up you get a capsule with random contents (champion shards, skin shards, etc) that you might be able to disenchant into BE, but it certainly won't be as much as the IP you would have collected in the current system over the course of the games you played to get from your previous level to the current one. That basically means that while the price of new champions stays the same, the currency just became several times harder to earn.
Basically they want you to drop a ton of money on garbage in the veteran shop so you won't have anything to buy new champions with, and because of the changes to the leveling and currency system, you will be essentially forced to buy new champions with money (or grind like 6-10 games a day). Don't fall for it, buy what you really really like and save the rest.